Morphology of the lateral superior temporal gyrus in neuroleptic naı̈ve patients with schizophrenia: relationship to symptoms

Abstract

Objective: The superior temporal gyrus (STG) is a large structure in the temporal lobe with multiple sub-regions that are structurally and functionally distinct. This study evaluates the structural morphology of a specific sub-region of the STG, the anterior and posterior portions of the lateral aspect of the STG. Furthermore, relationships between the morphology of these regions and symptoms of the illness were explored. Method: Regions of cortex were consecutively traced on a set of serial coronal slices in 25 male neuroleptic naı̈ve patients with first episode schizophrenia and 25 age-matched healthy volunteers. Regional gray matter volumes were calculated and compared, and their correlations with three symptom dimensions were explored. Results: The left anterior STG had a significant inverse correlation with psychotic symptoms, whereas the right posterior STG had a significant positive correlation with negative symptoms. These findings were confirmed by a follow-up analysis using extreme groups. There was no significant correlation between any region and disorganized symptoms. Conclusions: These findings suggest that abnormalities in the lateral side of the STG may be associated with both psychotic and negative symptoms through different pathophysiological mechanisms.